It is desirable to obtain a plane image of an inspection object prior to obtaining a tomographic image by an Optical Coherence Tomography (OCT). An image acquisition range of the OCT can be known by the plane image.
Therefore, such an apparatus that an optical system of the OCT and an optical system of a Scanning Laser Ophthalmoscope (SLO) to obtain the plane image of the inspection object are partially shared has been disclosed in the below-mentioned PTL 1. Such a technique that each of the optical system of the OCT and the optical system of the SLO has a light source for generating light having different oscillating wavelengths and a galvano mirror for main-scanning a measuring beam which is irradiated to the inspection object and a galvano mirror for sub-scanning it are used in common has been disclosed there. A dichroic mirror is used on an optical path adapted to share the optical systems.
Such a technique that the means for main-scanning the measuring beam and the means for sub-scanning it are separately provided for the optical system of the OCT and the optical system of the SLO has been disclosed in the below-mentioned PTL 2. Such a technique that a polygon mirror which can main-scan at a speed higher than that of the galvano mirror is provided for the optical system of the SLO has been disclosed there. In the OCT, since an image acquisition time which is determined by a response time (an exposure time and a transfer time) of a line sensor is later than a scanning speed of the polygon mirror, the galvano mirror is used. Such a technique that the means for sub-scanning is provided for each of the optical system of the OCT and the optical system of the SLO has been disclosed. The dichroic mirror is used on the optical path adapted to share the optical systems.